The ergonomic issue of three-dimensional displaying has always been existed. For instance, the three-dimensional videos may easily cause visual fatigue for viewers. In recent years, many research institutions have carried out various research investigations on the effect of the content of the three-dimensional video to humans, and the industry currently attempts to set a standard for three-dimensional display according to the results from the research investigations.
Among the current technologies, using disparity adjustment to reduce the viewer's visual fatigue while watching a three-dimensional video has been employed by majority in the related industries. Disparity adjustment is performed, mainly, according to a disparity range in the recent technologies. However, if only the disparity range of the three-dimensional video is considered, it is not enough for viewers to prevent from visual fatigue.